Whether doctors had been up doing emergency surgery the previous night did not affect a patient's risk of having complications during or after the procedure.
"Even if they have a surgeon who may be working long hours or is tired, they shouldn't be worried that he isn't capable of performing the surgery to the best of his ability," Nash told Reuters Health.
She worked on the study at the Institute for Clinical Evaluative Sciences in London, Ontario, Canada.
Previous studies had come to mixed conclusions on whether surgeon fatigue plays a role in how well an operation goes.
For their study, the researchers looked at records from non-emergency gallbladder surgeries performed by 331 surgeons at 102 community hospitals in Ontario.
Based on surgeons' billing for emergency procedures, they found 2,078 instances when the doctor had operated the night before a planned gallbladder removal.
For each of those surgeries, the researchers picked four others - 8,312 total cases - when a surgeon didn't operate the night before.
Regardless of whether doctors were up working the previous night, they had to make larger cuts than originally planned during about 2 percent of gallbladder surgeries.
Patients heal more slowly and have to stay in the hospital longer after those so-called open surgeries. So surgeons try to avoid making bigger incisions unless there's a problem, Nash said.
During just under 1 percent of surgeries by both sleep-deprived and non-sleep-deprived surgeons, patients suffered an injury that could have been caused by the doctor - like a punctured bowel or blood vessel.
Deaths were rare in both groups. Five or fewer patients died within a month of surgery when surgeons had operated the night before and seven when they had not, Nash and her colleagues report in the Journal of the American Medical Association.
Like any other person, surgeons are going to feel better and do better when they are well-rested, said Dr. Jordan Weinberg, who was not involved in the study.
But, he said, "We're trained from the get-go to be able to function to the best of our abilities under duress," including while low on sleep.
Weinberg, from the University of Tennessee Health Science Center in Memphis, has studied surgeon performance after overnight shifts.
Concern about long shifts and lack of sleep led the Accreditation Council for Graduate Medical Education to introduce restrictions on work hours for doctors-in-training in 2003 and again in 2011.
However, those restrictions have been controversial.
"The training now really emphasizes rest and breaks from duty, but in the real world, when you go into practice, those regulations don't exist," Weinberg told Reuters Health.
It's often not possible to provide timely care and have no doctors working overtime, he said.
For patients, Weinberg said there is nothing wrong with asking surgeons if they are rested for an elective procedure.
"In an ideal world, as a patient you obviously would want and expect your surgeon to be well-rested and in tip-top shape to perform your surgery," he said.
"If you came in for your elective surgery one morning and discovered that your surgeon had been in all night doing a complex case, it would be reasonable to say, âI want to schedule this for another day.'"
But that's not always easy to do, Weinberg added. Patients have already taken time off from work, and hospitals have already booked time in the operating room.
In an editorial published with the study, Dr. Michael J. Zinner from Brigham and Women's Hospital in Boston and Dr. Julie Ann Fresichlag from Baltimore's Johns Hopkins Medical Institute said surgeons should assess for themselves how tired they are before a procedure.
"It's something to be aware of as a patient," Weinberg said. But, "I don't think it should be a great cause for concern."
SOURCE: http://bit.ly/MvXYT6 Journal of the American Medical Association, online November 5, 2013.